Trustworthiness is a value considered to be a Virtue. A trustworthy person is someone in whom we can place our trust and rest secured that the trust will not be deceived.
A person can prove his trustworthiness by satisfying an assigned responsibility - and as an expansion of that, to not let down our expectations. The responsibility can be either material, such as delivering a mail package on time, or it can be a non-material such as keeping an important secret to him.
